Fix/suppress renderthread google-explicit-constructor warnings

* Add explicit to conversion constructors/operators
* Use NOLINT or NOLINTNEXTLINE to suppress warnings on intended converters

Bug: 28341362
Test: make with WITH_TIDY=1 DEFAULT_GLOBAL_TIDY_CHECKS=-*,google-explicit-constructor
Change-Id: Ib7d634bf1e0e9a1dda35b0a1d92de4d460193296
diff --git a/libs/hwui/renderthread/VulkanManager.h b/libs/hwui/renderthread/VulkanManager.h
index c319c9e..ea69704 100644
--- a/libs/hwui/renderthread/VulkanManager.h
+++ b/libs/hwui/renderthread/VulkanManager.h
@@ -127,6 +127,7 @@
             fPtr = ptr;
             return *this;
         }
+        // NOLINTNEXTLINE(google-explicit-constructor)
         operator FNPTR_TYPE() const { return fPtr; }
 
     private: